Brakeshoe punching apparatus



Dec. 23, 1969 F. A. CANADA BRAKESHOE PUNCHING APPARATUS Fil ed Jan. 2,1968 5 Sheets-Sheet 1 INVENTOR. 4 CANADA $11 FQAA/k' BY A 7'7'O/2/VEVSDec. 23, 1969 F. A. CANADA BRAKESHOE PUNCHING APPARATUS 5 Sheets-Sheet 2Filed Jam.- 2, 1968 INVENTOR. FQA/VK A CANADA BY 4 7" TOE/V5 V5 Dec. 23,1969 P. A. ANADA BRAKESHOE PUNCHING APPARATUS 5 Sheets-Sheet 3 FiledJan. 2, 1968 I NVENTOR.

a M M. W

BRAKESHOE PUNCH ING APPARATUS Filed Jam 2, 1968 5 Sheets-Sheet 4 '57Fla-12 FIb' 7/ 75 I mvsmron EQA'A/K A CANADA ATTORNEYS FIQI 6 Dec. 23.1969 F. A. CANADA 3,485,129

BRAKESHOE PUNCHING APPARATUS Filed Jan. 2, 1968 5Sheecs-Sheet 5 AM if65% 56 Q 58 1! p52 l L l l g. l

INVENTOR.

FIQ FRANK ,4. CANADA United States Patent O 3,485,129 BRAKESHOE PUNCHINGAPPARATUS Frank A. Canada, 13511 E. Valley Blvd.,

. La Puente, Calif. 91746 Filed Jan. 2, 1968, Ser. No. 695,093 Int. Cl.B26d /08, 7/02 U.S. Cl. 83-454 15 Claims ABSTRACT OF THE DISCLOSURESUMMARY OF THE INVENTION In the forming of rivet holes or holes for anyother purpose in a hollow cylindrical or semi-cylindrical structure,such as a brakeshoe, the holes are formed prior to shaping the structureinto its cylindrical form or the holes are formed one-at-a-time bymoving the workpiece past a single punch die. The present invention isto provide an apparatus for punching as many rivet holes or the like asneeded in a cylindrical work without moving the workpiece and includedin the objects of the invention are:

First, to provide an apparatus of this type in which a cylindrical orsemi-cylindrical workpiece is clamped by semi-cylindrical die holderscontaining a set of dies arranged radially and an eccentric rollerdriven by a shaft (located at the intersection of the set of radii)operates the dies progressively.

Second, to provide an apparatus of this type particularly adapted topunch riv-et holes in brakeshoes wherein the brakeshoe flange is heldbetween one pair of die holders and the rim is held between these dieholders as a unit and a third die holder.

Third, to provide an apparatus of this type wherein means are providedto move the die holders into clamping engagement for the punchingoperation or to separate them for insertion of a workpiece; theapparatus incorporating means whereby the die holders are locked inplace to prevent relative movement under the forces inherent in thepunching operation.

DESCRIPTION OF FIGURES FIGURE 1 is a front view of the brakeshoepunching apparatus with the die in its closed position.

FIGURE 2 is a side view thereof, also with the die in its closedposition.

FIGURE 3 is an enlarged fragmentary sectional view, taken through 33 ofFIGURE 2, showing the drag brake.

FIGURE 4 is a partial sectional, partial front view, taken through 4-4of FIGURE 6, showing the die in its open position.

FIGURE 5 is a fragmentary sectional view, taken through 5-5 of FIGURE 6,showing the die in its closed position.

FIGURE 6 is an enlarged fragmentary sectional view, taken through 66 ofFIGURE 1, showing the die in its open position.

FIGURE 7 is a sectional view, taken through 7-7 of FIGURE 5, with thepunch actuator omitted and with the upper die shown fragmentarily.

3,485,129 Patented Dec. 23, 1969 FIGURE 8 is an enlarged fragmentarysectional view, taken through 88 of FIGURE 1, with the die in its closedposition and showing one of the die units.

FIGURE 9 is an enlarged fragmentary sectional view, taken through 99 ofFIGURE 4, with the die shown in its closed position and showing one ofthe alignment pins.

FIGURE 10 is an enlarged fragmentary sectional view, taken within circle10 of FIGURE 1, showing a pressure pm.

FIGURE 11 is an enlarged fragmentary sectional view, taken through 1111of FIGURE 1, with the die shown in its closed position and showing apair of opposed positioning and clamping pins.

FIGURE 12 is an enlarged fragmentary sectional view, taken through 1212of FIGURE 18, showing the clutch dog.

FIGURE 13 is a fragmentary sectional view, taken through 13-13 of FIGURE12.

FIGURE 14 is an enlarged fragmentary sectional view, taken through 14-14of FIGURE 18.

FIGURE 15 is a perspective view of the clutch dog.

FIGURE 16 is an enlarged fragmentary partially sec tional, partiallyside view of the clutch mechanism, taken within circle 16 of FIGURE 2.

FIGURE 17 is a fragmentary sectional view, taken through 1717 of FIGURE16.

FIGURE 18 is a fragmentary sectional view, taken through 1818 of FIGURE16.

FIGURE 19 is a fragmentary sectional view, taken through 1919 of FIGURE16.

For purposes of illustration, the apparatus is shown as arranged for thepunching of rivet holes in a brakeshoe. The conventional brake shoe Sincludes a semi-cylindrical rim R from which extends a radially inwardlydirected flange F.

The apparatus includes a table 1, on which is mounted a verticallydisposed front plate 2, and a back frame 3 connected by horizontal beams4.

Mounted near lateral sides of the front plate at the forward sidethereof is a pair of vertically extending guide bars '5. Slidablymounted between the guide bars, by means of guide sleeves 6, is abacking block 7, having an upwardly directed concave face 8. The bottomend of the backing block 7 is joined by a yoke 9 to a piston rod 10extending from a hydraulic power unit 11, supported by a frame 12,suspended under the table 1.

Mounted within the concave face 8 of the backing block 7, is a concaveor semi-cylindrical die holder 13. The die holder is secured in place bymeans of vertical retaining pins 14 and horizontal retaining screws 15.It is intended that a set of die holders be provided, having differentinternal diameters, but interchangeably retainable in the backing blockby the pins 14 and the screws 15.

The die holder 13 is provided with a set of radially extending diereceiving bores 16 which may be in the same plane or in different planesdepending upon the desired location of the rivet holes to be formed inthe brakeshoe rim. Each bore 16 receives a die collar or female die 17.The die receiving bores communicate with a chip receiving channel 18,which in turn communicates with one or more outlet openings 19.

Secured to the upper portion of the front plate 2, in vertical alignmentwith the concave die holder 13, is a fixed convex die holder 20. The dieholder 20 is secured by mounting bolts 21, and in addition, is heldagainst displacement by backing blocks 22. The fixed convex die holder20 is approximately half the axial dimension of the concave die holder13.

A second convex die holder 23, having dimensions similar to the dieholder 20, is located in front of the die holder 20. The die holder 23is supported relative to the 3 die holder 20 by means of horizontalguide pins 24. The

die holder 23 is also supported by a cross bar 25, se-

cured to the lateral margins of the front plate 2. The horizontallymovable die holder 23 is connected by a yoke 26, to a piston rod 27extending from a hydraulic power unit 28 secured to the cross bar 25.

The die holders 20 and 23 are provided with radial die bores 29, eachcontaining a male die unit 30. Each die unit includes a guide bushing 31at the radially outer end of the corresponding die bore, which is heldin place by screws 32. Each guide bushing slidably receives a die pin 33which is provided at its radially inner end with a head 34. A returnspring 35 is interposed between the bushing 31 and the head 34, all asshown best in FIGURE 8. The male die units are so located that when theconcave die holder 13 and the two convex die holders 20 and 23 clamp therim R of a brakeshoe S therebetween, each die pin 33 is in axialalignment with the corresponding die collar 13. The head 34 of eachpunch die unit protrudes radially inward into a semi-circular recess 36formed in each die holder 20 and 23; that is, each die holder is in theform of a hollow semi-cylinder.

A drive shaft 37 is located with its axis coinciding with the points ofintersection of the various punch die units. The drive shaft issupported in a pair of ball bearings 38 located in the upper portion ofthe front plate 2, and the back frame 3. In addition, the drive shaft issupported in a sleeve bearing 39 provided in a mounting block 40-,carried by the backing blocks 22. Between the forward ball bearing 38and the sleeve bearing 39, the shaft is provided with a pair ofeccentric rollers 41. Each eccentric roller includes an eccentricmounting collar 42 and a roller bearing, having an inner race 43,rollers 44 and an outer race 45. The outer race forms a pressure ring,which when the roller moves eccentrically, bears against the heads 34 ofthe punch die units.

The confronting sides of the die holders 20 and 23 define a brakeshoeflange slot 46. This slot is intersected by opposed positioning andclamping pins 47, backed by springs 48. The pins 47 permit a brakeshoeto be thrust manually and be held in place until the concave die holderhas been raised into operating relation with the die holders 20 and 23.

It is preferred that the brakeshoe not be pressed fully into place bymanual operation. Instead, a pair of radially extending pressure pins 49are provided, which are backed by springs, preferably in the form ofBellevue washers, 50, as shown in FIGURE 10. When the die holder 13 ismoved away from the die holders 20 and 23, the pressure pins force thebrake shoe rim R a short distance away from the holders 20 and 23, sothat the brakeshoe may be manually engaged for removal.

Inasmuch as it is essential that both die holders 20 and 23 be in properradial alignment with the die holder 13, the die holder 20 is accuratelypositioned by alignment pins 51, indicated in FIGURE 9, and the dieholder 23 is properly located radially by its horizontal guide pins 24and its abutment contact with the die holder 20.

In order to assure that the die holder 13 is in place, and will not movein response to any force exerted by the die pins 33, a pair of lockingbars 52, shown best in FIG- URE 7, are movable horizontally through thefront plate 2 and into sockets '53 provided in the die holder 13. Thelocking bars 52 are connected by a crossbar 54 which in turn is joinedby a pair of links 55 to a lever 56, pivotally supported by a bracket57, The lever 56 is connected to a piston rod 58 extending from ahydraulic power unit 59.

The drive shaft 37 is operated by a drive motor 60, connected through abelt 61 to a gear reduction unit 62, which in turn is connected by abelt 63 to a flywheel 64 mounted on the shaft 37 behind the back frame3, as indicated in FIGURE 2.

The flywheel is provided with a clutch collar 65, indicated in FIGURES12, 13, 16 and 19. The collar 65 is provided with a clutch slot 66 whichis engaged by a clutch dog 67. 'Theclutch dog is carried by a clutchcollar 68 mounted on the shaft 37. The clutch dog is sl idably mountedin a socket 69 and backed by a spring 70. The outer end of the dog isbeveled to form a latch tip 71 which confronts the clutch collar toengage the notch 66, as indicated best in FIGURE 12. Outward movement ofthe clutch dog is restrained by a. stop plate 72 which fits within arecess 73 and is held there by a retainer clip 74. The stop plate alsorestrains the clutch dog against rotation in its socket 69.

The clutch dog is provided with a side slot- 75, having a cam surface76. The clutch collar 68 is provided with an annular channel 77 whichexposes the side slot and receives a tip 78 of a trip .bar 79 suitablysupported .on the back frame 3 by a guide plate 80. The trip bar isconnected to a lever 81 which is urged by a spring 82 in a direction tourge the tip 78 of the trip bar into the side slots 75. The lever 81 issuitably connected, by means not shown, to an operating handle 83mounted at one side of the front plate 2. y

In order to control overtravel of the shaft 37, a drag brake 84 isprovided, as shown.best in FIGURE 3. The drag brake includes a pair ofclamp members 85 which fit over opposite sides of the shaft and arepivotally connected to a common mounting boss 86. The clamp members arealso joined by a tie bolt 87 which carries a spring 88. The confrontingsides of the clamp members 85, which are semi-cylindrical, are providedwith brakeshoes 89 which engage a collar 90 secured to the shaft 37.

Operation of the brakeshoe punching apparatus is as follows:

The brakeshoe flange slot 46 is profiled so as to correspond to theflange of a particular style of brakeshoe. Thus, a brakeshoe having theproper flange profile is inserted between the die holders 20 and 23 whenthe die holders are slightly separated. The brakeshoe is held in placeby the clamping pins 47. The die holder 13 is then thrust upwardly toclamp the rim R against the radially outer surfaces of the die holders20 and 23. Prior to this, the die holder 23 is closed against the dieholder 20. It is not intended by this operation to clamp the flange Ftightly, as variations in the thickness of the flange would preventproper axial alignment of the punch die components. When the rim isproperly clamped, the operating handle 83 is moved to cause release ofthe clutch dog 67 from the tip 78 so that the latch tip 71 can engagethe slot 66 whereupon the flywheel rotates the shaft 37 and causes theouter races or pressure rollers 45 to engage the heads 34 of the punchdie units 30. Such engagement stops the pressure roller from rotatingwith the shaft, but does cause the pressure roller to move radially inan eccentric path so that the die pins 33 are forced radially outwardand in a progressive manner causing the actual punching of the holes tooccur in rapid sequence rather than simultaneously. When the punchingoperation is complete, the cam surface 76 is engaged by the tip 78 ofthe trip bar and the dog is retracted, whereupon the drag brake quicklystops further rotation of the shaft 37.

The die holder 13 is then retracted. First, however, releasing thelocking bars 52. Also, the die holder 23 is removed a short distancefrom the die holder 20. This movement may be sufiicient that theclamping pins 47 disengage the brakeshoe flange F so that the brakeshoemay drop free, aided by the action of the pressure pins 49.

While particular embodiments of this invention have been shown anddescribed, it is not intended to limit the same to the details of theconstructions set forth, but instead, the invention embraces suchchanges, modifications and equivalents of the various parts and theirrelationships as come within the purview of the appended claims.

I claim:

1. An apparatus for punching apertures in workpieces of cylindricalform, comprising:

(a) mating radially inner and radially outer die holders defining acylinder;

(b) means for forcing said die holders into clamping engagement with acorrespondingly contoured workpiece therebetween;

(c) a set of punching dies extending radially with respect to said diehodlers, each die having a moving component disposed in said radiallyinner die holder and a mating component in said radially outer dieholder;

((1) and operating means for moving the movable components of said diesradially to penetrate said workpiece.

2. An apparatus, as defined in claim 1, wherein:

(a) said operating means includes a rotatable shaft radially inward ofsaid punching dies and an eccentric roller mounted thereon and having anouter pressure ring for operating said punching dies.

3. An apparatus, as defined in claim 1, wherein:

(a) a pair of radially inner die holders is provided, movable as a unitwith respect to said outer die holder;

(b) and means effecting relative movement of said inner die holdersperpendicular to the relative radial movement of said inner and outerdie holders, thereby to receive therebetween a workpiece having aradially extending flange.

4. An apparatus, as defined in claim 1, which further comprises:

(a) means operable independently of said clamping means for locking saidouter die holder against displacement by the force exerted on operationof said punching dies by said operating means.

5. An apparatus for punching rivet holes in brakeshoes,

comprising:

(a) a radially outer concave die holder;

(b) a radially inner convex die holder;

(c) a set of punching dies having radially movable inner componentsdisposed in said inner die holder, and fixed outer die componentsdisposed in said outer die holder;

(d) means for effecting relative movement of said die holders to clampthe rim of a brakeshoe therebetween;

(e) and operating means for effecting radial movement of said movabledie components to punch said rim.

6. An apparatus, as defined in claim 5, wherein:

(a) said operating means includes a shaft having an axis passing throughthe point of intersection of the axes of said set of punching dies, andan eccentric roller progressively engageable with said movable diecomponents to operate said dies in sequence.

7. An apparatus, as defined in claim 5, wherein:

(a) a pair of inner die holders disposed on opposite sides of saidbrakeshoe flange are provided and are radially movable to and from saidflange;

(b) and two sets of said dies are provided for punching said rim onopposite sides of said flange.

8. An apparatus, as defined in claim 7, which further comprises:

(a) means for locating said inner die holders and said pieces definingat least a portion of a cylinder, said apparatus comprising;

(a) an operatingshaft located at the axis of said workpiece;

(b) at least one eccentric pressure ring journalled on said shaft, saidshaft being rotatable in said ring to cause a prpgressive radialextension and retraction of the surface of said ring;

(0) an inner die holder of arcuate form, having a radially inner sideconfronting said pressure ring; (d) a plurality of radially movablepunching die elements mounted in said die holder and having radiallyinner ends engageable in sequence by said pressure ring to effect radialmovement of said dies;

(e) a radially outer die holder having a concave side confrontingtheradially outer side of said inner die holder;

(f) means for moving said die holders radially for clamping saidworkpiece between said die holders;

(g) and fixed die elements in said outer holder adapted to be alignedwith said movable die elements when said work piece is clamped.

11. An apparatus, as defined in claim 10, wherein:

(a) said inner die holder is fixed and mounted above said outer dieholder;

(b) said moving means is a hydraulic power unit to reciprocate saidouter die holder;

(c) and means independent of said moving means locks said outer dieholder in position to place said die elements in radial alignment.

12. An apparatus, as defined in claim 10, wherein:

(a) a second inner die holder is mounted in axial alignment with thefirst die holder for movement relative thereto.

13. An apparatus, as defined in claim 12, wherein:

(a) said first inner die holder is fixed, said second inner die holdermoves axially relatively thereto and said inner die holders are adaptedto receive a radially extending portion of a workpiece therebetween;

(b) said outer die holder moves radially with respect to both inner dieholders;

(0) a set of radially movable die elements is contained in each of saidinner die holders;

(d) and twomating sets of die elements are carried by said outer dieholder.

14. An apparatus, as defined in claim 10, wherein:

(a) means is provided to effect a single rotation of said shaft.

15. An apparatus, as defined in claim 13, which further comprises:

(a) axially movable yieldable clamping means carried by said inner dieholders for engaging and holding the flange of the brakeshoe prior toengagement of said outer die holder, said yieldable clamping meansadapted to release said flange on axial separation of said inner dieholders.

References Cited UNITED STATES PATENTS 1,419,619 6/1922 Edwards et a1.83-382 X 1,663,443 3/1928 DArdenne 83-519 1,946,991 2/1934 Tormyn et a183- 618 X ANDREW R. JUHASZ, Primary Examiner JAMES F. COAN, AssistantExaminer U.S. Cl. X.R.

